1. Field of the Invention
The present invention relates to an adjustable reflector of a head-up display, and more particularly, to an adjustable reflector of a head-up display with simplified structure and improved image stability.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a diagram showing a head-up display of the prior art. Generally, the head-up display 100 of the prior art comprises an image source 110, a lens 120, a reflecting mirror 130 and an optical combiner 140. A light beam L generated by the image source 110 is refracted by the lens 120, and then reflected to the optical combiner 140 by the reflecting mirror 130. The light beam L reflected to the optical combiner 140 forms a virtual image and/or a real image for providing driving information, such as vehicle speed information, time information and navigation information, to driver. Since different drivers have different heights and seating positions, in order to allow the drivers to easily see the information displayed by the head-up display, a reflection angle of the reflecting mirror 130 can be adjusted to reflect the light beam L to an appropriate position on the optical combiner 140. For example, when the driver is shorter, the head-up display 100 can rotate the reflecting mirror 130 for moving an incident position of the light beam L from a first position P1 to a second position P2, which is a lower position, on the optical combiner 140.
In the head-up display 100 of the prior art, the reflecting mirror 130 is fixed to a rotary shaft 150, and the rotary shaft 150 is driven by a motor to rotate, in order to further adjust the reflection angle of the reflecting mirror 130. However, the motor needs to cooperate with a complex gear speed reduction mechanism to drive the rotary shaft 150 for controlling the reflection angle of the reflecting mirror 130 precisely. Therefore, the head-up display 100 of the prior art has a more complex structure. Moreover, the reflecting mirror 130 is only fixed to the rotary shaft 150 without being supported by other elements. Thus the reflecting mirror 130 is easily deflected by shock, such that the head-up display 100 has lower image stability.